Fix T99737: Dropping files fails with Wayland

Drop events ignored the cursor coordinates, under the assumption that
cursor motion events would also be sent to update the cursor location.

This depended on the behavior of the compositor, it failed for Sway
but worked for Gnome-shell & River.

Resolve by making use of the drop events cursor coordinates.

source/blender/windowmanager/intern/wm_window.c

@@ -1362,6 +1362,11 @@ static bool ghost_event_proc(GHOST_EventHandle evt, GHOST_TUserDataPtr C_void_pt
         event.type = MOUSEMOVE;
         event.val = KM_NOTHING;
         copy_v2_v2_int(event.prev_xy, event.xy);
+
+        wm_cursor_position_from_ghost_screen_coords(win, &ddd->x, &ddd->y);
+        event.xy[0] = ddd->x;
+        event.xy[1] = ddd->y;
+
         event.flag = 0;
 
         /* No context change! C->wm->windrawable is drawable, or for area queues. */